I've now purchased 3 Keurigs, all different models and none of them have lasted more than 6-7 mths.  Most recent was an industrial model and it lasted 3 1/2 months.  There is only two of us and my husband is only home on weekends so they don't get used a lot.  We are on good town water and don't get a lot of build up.
Love the concept but having to purchase at least one a year doesn't warrant the cost.